In this post Yunpeng Luo, an ecologist at The Swiss Federal Institute for Forest, Snow, and Landscape WSL, shares insights from his recent work “Internal physiological drivers of leaf development in trees: Understanding the relationship between non-structural carbohydrates and leaf phenology”. He highlights that plants’ carbon sink-source activities and concentration of non-structural carbohydrates could be the key eco-physiological drivers that influence the plant phenology. Additionally, he emphasizes that interdisciplinary collaboration and supportive senior colleagues can spark new ideas and significantly empower career development for young researchers.
About the paper
Our research examines the seasonal dynamics of non-structural carbohydrates (NSC) across different tree organs and their relationship with leaf or needle phenology in deciduous and evergreen trees. While much of the existing literature has focused on how environmental factors like temperature and daylength influence leaf emergence and senescence, the impact of intrinsic physiological factors has received less attention. Inspired by Dr. Constantine Zohner’s 2023 study published in Science, which revealed that increased temperatures prior to the summer solstice advance leaf senescence while those after the solstice delay it, we seek to uncover the physiological mechanisms behind this phenomenon. We hypothesize that the activities of carbon sources (photosynthesis) and sinks (e.g. tree growth and respiration) are crucial in shaping the carbon balance within trees. Specifically, we propose that the NSC concentration, which reflects the balance between these source-sink dynamics, may be key physiological traits influencing both spring leaf-out and senescence.
To test this hypothesis, we propose a multi-scale approach that integrates several methodologies. This includes manipulative experiments, large-scale network observations, remote sensing, and carbon allocation modelling. By employing these approaches, we aim to gain a deeper understanding of the relationship between non-structural carbohydrates and phenology in trees.
About the research
At the time we conceived this review and perspective paper, most phenology studies were still striving to uncover how environmental cues influence changes in plant phenology. Therefore, we are encouraged and gratified by the editor and reviewers’ remarks that our study may open new avenues for research. Although our work offers fresh perspectives on understanding the drivers of plant phenology, we believe there is still much to be done within the ecological community to fully comprehend the relationship between carbon sink-source dynamics, non-structural carbon (NSC), and leaf phenology. For instance, in our efforts to delineate the seasonal dynamics of NSC in various tree organs (e.g., leaves and branches) by referencing existing literature, we found that previous NSC observations are often temporally sporadic (with measurements typically taken monthly). This has limited the accuracy of descriptions regarding NSC seasonal dynamics. Furthermore, our understanding of carbon allocation and the precise interaction mechanisms between different organs remains inadequate. This limitation hinders the spatial modeling of non-structural carbon and poses challenges in linking changes in leaf phenology with NSC dynamics on a larger scale.
We therefore suggest that future research should focus on enhancing our understanding of the seasonal dynamics of NSC and carbon allocation in different tree organs, particularly during critical transitional periods such as leaf-out, the summer solstice, and the onset of leaf senescence. This can be achieved through manipulative experiments and more intensive observational studies.
About the author
I first became involved in ecological research thanks to the inspiration of my supervisors—Prof. Changhui Peng, Prof. Huai Chen, and Prof. Qiu’an Zhu—during my bachelor’s and master’s studies. After obtaining my Ph.D. at the Max Planck Institute for Biogeochemistry, I joined the Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL) as a postdoctoral researcher. I feel lucky enough to have been supervised by world-renowned scientists and to have gained experience in prestigious research institutions. These experiences have deepened my understanding of how to conduct rigorous science, the importance of topic and time freedom in research, and my potential responsibilities and values within the scientific community.
I am especially grateful to work with supportive supervisors like Prof. Arthur Gessler and Dr. Mirco Miglivacca, who serve as exemplary role models. The brilliant coauthors, such as Prof. Andrew Richardson, have generously shared their insights, inspiring me to think more deeply. Being part of dynamic, enjoyable, and productive teams has also highlighted for me how crucial strong leadership is in fostering an engaging scientific environment, as exemplified by Prof. Markus Reichstein and Prof. Arthur Gessler. Echoing Dr. Seraina Cappelli’s advice, I believe it’s essential to work with kind and supportive individuals. Follow their example, and I am sure you will enjoy your science journey and potentially make the world a little bit better 😉
Read the research article here.
